Update dependency markdownlint-cli to v0.21.0

Author: renovate-bot

package.json

@@ -102,7 +102,7 @@
     "husky": "3.0.9",
     "jest": "24.9.0",
     "lint-staged": "8.2.1",
-    "markdownlint-cli": "0.20.0",
+    "markdownlint-cli": "0.21.0",
     "opn": "5.5.0",
     "prettier": "1.18.2",
     "raf": "3.4.1",

yarn.lock

@@ -4599,6 +4599,11 @@ ignore@^3.3.3, ignore@^3.3.5, ignore@^3.3.6:
   resolved "https://registry.yarnpkg.com/ignore/-/ignore-3.3.10.tgz#0a97fb876986e8081c631160f8f9f389157f0043"
   integrity sha512-Pgs951kaMm5GXP7MOvxERINe3gsaVjUWFm+UZPSq9xYriQAksyhg0csnS0KXSNRD5NmNdapXEpjxG49+AKh/ug==
 
+ignore@~5.1.4:
+  version "5.1.4"
+  resolved "https://registry.yarnpkg.com/ignore/-/ignore-5.1.4.tgz#84b7b3dbe64552b6ef0eca99f6743dbec6d97adf"
+  integrity sha512-MzbUSahkTW1u7JpKKjY7LCARd1fU5W2rLdxlM4kdkayuCwZImjkpluF9CM1aLewYJguPDqewLam18Y6AU69A8A==
+
 import-fresh@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/import-fresh/-/import-fresh-2.0.0.tgz#d81355c15612d386c61f9ddd3922d4304822a546"
@@ -6117,15 +6122,16 @@ markdown-it@10.0.0:
     mdurl "^1.0.1"
     uc.micro "^1.0.5"
 
-markdownlint-cli@0.20.0:
-  version "0.20.0"
-  resolved "https://registry.yarnpkg.com/markdownlint-cli/-/markdownlint-cli-0.20.0.tgz#838c61bf43a3bce4dcde1a32acd80e31116bba9a"
-  integrity sha512-5VCGS+9w/mVMVDHrKOciq+ZXYdFEypyuCvCdNjHdji8itqcryWMr7V2NdpxQ/KeJmMNoRYsdc2R+88lSc+2gpA==
+markdownlint-cli@0.21.0:
+  version "0.21.0"
+  resolved "https://registry.yarnpkg.com/markdownlint-cli/-/markdownlint-cli-0.21.0.tgz#d792b157e9de63ce1d6b6e13d7cf83d5e552d5e8"
+  integrity sha512-gvnczz3W3Wgex851/cIQ/2y8GNhY+EVK8Ael8kRd8hoSQ0ps9xjhtwPwMyJPoiYbAoPxG6vSBFISiysaAbCEZg==
   dependencies:
     commander "~2.9.0"
     deep-extend "~0.5.1"
     get-stdin "~5.0.1"
     glob "~7.1.2"
+    ignore "~5.1.4"
     js-yaml "~3.13.1"
     jsonc-parser "~2.2.0"
     lodash.differencewith "~4.5.0"